Hire the Best Bitcoin Developers in Dnipro, UA

Thank you for viewing my profile! I have been working as a freelancer/remote developer for more than 10 years solo as well as in a team. I have experience in full stack development from scratch to release, including backend and iOS/Android applications. and Web3 projects. My latest Golang/Crypto works include EVM/Solana trading bot and Solana token prices indexer. My latest python/crypto works include arbitrage app for bsc, frontrunning & backrunning bots, txs repeater bot, blockchain scanner-analytical bot and rest apis for the mobile apps. My latest mobile works include social media analytics app, bitcoins exchange app, customizable weather app, fax app, encrypted photo album app, document editor app, whatsapp companion app for Apple Watch, QR code scanner/generator app. Skills: Golang development: Golang, MongoDB, ClickHouse, Rust, TXs decoding, REST API, Websockets, EVM & Solana nodes maintenance, Telegram API Python development: Python, GETH for ETH & BSC nodes, Web3, networking, sqlite, PostgreSQL, Rest api, firebase, telegram api, bloxroute, frontrunning txs, custom routers, arbitrage swaps etc. Android development: Android SDK, Kotlin, RxKotlin, Synthetic, Kotlin Android Extensions, Dagger 2, Git, RxJava, Java, AndroidX, RxDatabinding, Navigation Components, Realm, Room, SQLite, NoSQL, SQL, OpenGL, Retrofit, REST json, Butterknife, Picasso&Glide, Firebase SDK (cloud functions, cloud messaging, storage, push notifications, social auth), Google console, Google Maps API, Yandex Kassa API&SDK, Dropbox SDK, java sockets, Crashlytics, Widgets, Generating&Scanning QR codes, VK SDK, FB SDK, Android keystore, Android fingerprint, OpenCSV, apk uploading to play market, familiarization with software development methodology, good knowledge design patterns, MVVM/MVP/MVC, clear code, Scrum, Kanban methodology, asana, trello task tracker, interesting in blockchain projects. IOS development: IOS SDK, WatchOS SDK, WatchKit, WatchConnectivity, Swift, RxSwift, Alamofire, CoreData, RealmSwift, Realm, RxRealm, Kingfisher, Swinject, UIKit, WebKit, MVP/MVVM/MVC, Firebase SDK, CoreLocation, Cocoapods, Git, SourceTree, XCode.

Is your blockchain product ready for real users, or is it a prototype that breaks under live transactions? Most Web3 projects fail at the boundaries between smart contracts, wallets, trading operations, and backend systems. 🏆 20+ years architecting production systems at principal engineer level 📊 $200K+ earned on Upwork across 32 architecture projects 🎯 100% Job Success Score, Top Rated Plus on Upwork ⚡ 11 years architecting Fintech / Trading / Accounting solutions ⚡ 8 years architecting blockchain products across Bitcoin, EVM, Solana ecosystems 💼 CEO at Osambit, a 20-person engineering team ✅ Enterprise Blockchain Architect certified, former Sr Principal Engineer at Nordstrom ⭐⭐⭐⭐⭐ "We've had the opportunity to collaborate with the Osambit team, and it's been a great experience. They're highly professional, responsive, and truly understand the final goal. Their technical expertise and ability to deliver on time have been key to the success." (Alwyn V., IXO World) As a Blockchain Architect with 20+ years of production engineering experience and two years focused on Web3, I design blockchain and fintech products that operate reliably beyond a demo. I work across Solana and EVM networks—including Ethereum, Polygon, Base, BSC, and Arbitrum—as well as enterprise platforms such as Hyperledger Fabric and Besu. My work connects secure smart-contract, wallet, payment, and remittance flows with the backend systems, operational controls, and user experiences a real product needs. Every engagement starts with architecture: chain selection, custody and transaction boundaries, compliance-aware workflows, failure modes, scalability, and security. That architecture-first approach helps blockchain and neobanking products withstand live usage, not just testnet scenarios. 🔶 Centralized exchange: architecture for trading operations, wallet flows, and reliable backend integration 🔶 Custodial wallets: secure custody, transaction handling, and multi-wallet platform architecture 🔶 Trading automation system: real-time blockchain-integrated trading workflows with operational safeguards 🔶 Liquidity automation system: DeFi and liquidity-management automation across Solana and EVM ecosystems 🔶 Fintech, neobanking & remittance apps: payment, account, wallet, and cross-border transfer architecture 🔶 Bitcoin mining facility control panel: operational dashboard and control-system architecture for mining infrastructure 🔶 Blockchain-integrated game: NFT features, token and wallet integrations, and production-ready game backend design 🔶 Enterprise blockchain solutions: permissioned-network architecture and public-chain integrations using Hyperledger Fabric or Besu 🔶 Nordstrom (Sr Principal Engineer, 5 years): architected 9+ enterprise systems | led 10 offshore engineering teams | supply chain, payment, logistics domains WHAT I DO ✅ Blockchain Architecture: chain selection, system design, security boundaries, and production rollout planning ✅ Solana Development: Rust programs, SPL standards, RPC integrations, and high-throughput DeFi systems ✅ EVM & Smart Contracts: Solidity development and integrations for Ethereum, Polygon, Base, BSC, and Arbitrum ✅ Wallet & Custody Systems: custodial wallet architecture, secure transaction handling, and multi-wallet integrations ✅ Fintech, Neobanking & Remittance: payment flows, account and wallet systems, cross-border transfers, and operational controls ✅ DeFi, Trading & Liquidity Automation: trading workflows, liquidity systems, DEX integrations, and operational controls ✅ NFT & Tokenized Products: NFT minting, metadata, marketplace and royalty logic, and blockchain-integrated game features ✅ Enterprise Blockchain: Hyperledger Fabric and Besu solutions, permissioned-network architecture, and API or oracle integrations ✅ Full-Stack Web3 Platforms: React interfaces, Node.js or Python backends, web3 integrations, and real-time transaction services ✅ Production Infrastructure: AWS, Docker, Kubernetes, CI/CD, observability, automated testing, and scalable data systems WHO I WORK WITH 🎯 B2B and B2C companies building blockchain products, fintech and neobanking apps, exchanges, wallets, DeFi platforms, or games 🎯 Founders and CTOs who need Web3, payment, or remittance systems running in production with real users and real assets 🎯 Teams with multi-week engagements (4+ weeks minimum), not 5-minute tasks 🎯 Companies that understand blockchain architecture is a system design and security problem, not just a smart-contract problem 🎯 Clients who value senior engineering judgment over the cheapest hourly rate MY PROCESS 1️⃣ Architecture Review: 24-hour turnaround on an initial system map, risk review, and scope estimate for your blockchain or fintech product. Close collaboration with business and deep domain immersion. 2️⃣ Design: chain selection, smart-contract, wallet, payment, and remittance boundaries, backend integration, and security plan 3️⃣ Build: production blockchain or fintech

I possess a deep understanding of both business and technical processes, along with extensive expertise in web-based and client-server computing models. My experience encompasses system architecture development and analysis, application development lifecycle management, and providing business solutions and problem resolution. With 15 years of programming experience, 4 years in network management and system administration, and 6 years of user support and consulting, I bring a well-rounded skill set to the table. I am highly proficient in a wide range of programming languages, including: JavaScript – 15 years of experience PHP – 15 years of experience Additionally, I have specialized expertise in: PHP Yii Frameworks – 15 years of experience with over 40 successful projects PHP Yii2 Frameworks – 10 years of experience with over 50 successful projects I also have extensive experience in developing and maintaining legacy projects.

My name is Vitaliy, and I am a designer. I specialize in creating logos and corporate identity. I don't just draw beautiful pictures—I create logos that carry meaning, reflect the nature of your business, and convey the emotions of your brand. You can learn more about my approach to work by viewing my portfolio

I'm a Senior Python Developer and Full-Stack Engineer with 10+ years of experience, specializing in Django, FastAPI, and scalable backend systems. My expertise covers Payment Systems, E-Commerce Platforms, API Development, and Cloud Automation, helping businesses build secure, high-performance applications that scale. 🚀 What I Offer Backend & API Development Deep expertise in Django, FastAPI, Flask for building robust web apps and async APIs Microservices & API architecture with REST, GraphQL, gRPC, WebSockets Secure auth flows with OAuth2, JWT, OpenID High-performance async programming (asyncio, multiprocessing) Payment Systems & E-Commerce Experience with crypto payments (Ethereum, BNB, Bitcoin) PCI-DSS compliant solutions with 3D Secure, tokenization, and fraud prevention Built custom e-commerce platforms and integrated Shopify, WooCommerce, Magento APIs Expertise in subscription billing, marketplaces, and headless e-commerce Databases & Scaling SQL (PostgreSQL, MySQL) & NoSQL (MongoDB, Firebase, Cassandra) ORMs: Django ORM, SQLAlchemy, Prisma Performance optimization with Redis, Memcached, Celery High-load systems (1M+ transactions/day, real-time monitoring dashboards) Cloud & DevOps Docker, Kubernetes, Terraform, AWS (Lambda, ECS, S3, CDK), GCP, Firebase CI/CD with GitHub Actions, GitLab CI, Jenkins Serverless architectures for cost-efficient scalability Frontend (Full-Stack) React, Next.js, TypeScript, JavaScript UI frameworks: TailwindCSS, Material UI, Styled Components Testing with Pytest, Selenium, Postman 🏆 Case Studies & Achievements FinTech Platform (FastAPI + PostgreSQL + Redis) → Handled $20M+ annual transactions, integrated 5+ gateways. SaaS Platform (Django + React) → Used 10M+ users, real-time data sync, role-based access. E-Commerce AI Engine → Recommendation system boosted conversions by 40%. Monolith → Microservices Migration (FastAPI + Docker + Kubernetes) → 70% downtime reduction, 5x faster deployments. Crypto-Payment Gateway (Flask + Web3.py) → Secure ETH & BNB payments for NFT marketplace. Custom Subscription Billing Engine (Django + Stripe) → Coupons, trials, pro-rata billing, analytics. 💡 Why Work With Me? 15+ years of hands-on Python & full-stack experience Expert in secure payment systems & high-load e-commerce Strong problem-solving mindset with business-driven solutions. Clear communication, reliability, and deadline focus. 📬 Let's Build Something Great Together Need a Python/Django expert to architect a scalable system, implement secure payment flows, or elevate your e-commerce platform to the next level? Get in touch today and let's turn your idea into a fully working product!

🚀 Top-Rated and Expert-Vetted Senior iOS Developer with 10 Years of Mobile Expertise 📱 Are you in need of a seasoned iOS developer with a wealth of experience and a proven track record in building top-notch mobile apps? Look no further! I'm here to enhance your projects and take them to new heights. ✨ Why You Should Collaborate with Me: 📚 Master's Degree in Computer Science: My deep academic background ensures a strong foundation in software engineering principles, empowering me to craft efficient, high-quality code. 🤝 Proactive and Detail-Oriented: I bring a proactive mindset and keen attention to detail to every project, delivering not just solutions but polished products that shine. 🌍 Global Experience: I've partnered with startups worldwide, from the USA and UK to The Netherlands. This international exposure has enriched my skill set and allows me to bring diverse perspectives to your projects. 📱 Full-Stack Expertise: I specialize in developing native iOS apps using Swift, creating elegant and intuitive user interfaces and experiences. From ground-up builds to enhancing existing apps, I do it all. 🤖 Collaborative Cross-Functional Work: I thrive in cross-functional teams, collaborating seamlessly with product owners, designers, mobile developers, and backend experts to create holistic solutions. 🧩 Strong Problem-Solving Skills: Complex challenges don't deter me; I embrace them with analytical prowess and innovative thinking. 🏆 Recent Achievements: 🌟 I spearheaded the development of an e-commerce app for an Amsterdam startup that raised a staggering $120 million. 🌟 Another success story is a second phone number app, delivering calls and messaging features. Ready to take your projects to the next level, I'm excited to work with you and your team. Let's build the future together! 📈💼📱 ⚙️ Tools and Skills: 🛠️ Development Tools: Xcode Swift SwiftUI RxSwift Combine Apollo GraphQL Jira Confluence Git SwiftLint SwiftGen Dependency Injection 🎨 UI/UX Design: Figma Sketch Interface Builder Storyboards SwiftUI Preview Lottie 🧩 Frameworks and Libraries: Alamofire Moya Facebook SDK Algolia Iterable RevenueCat Twilio Stripe Realm Stream Chat One Signal Kingfisher 📱UI: UIKit Foundation SnapKit 📊 Analytics: Segment Firebase Google Analytics Mixpanel Amplitude Rollbar Crashlytics 🐞 Debugging and Testing: XCTest XCUITest Quick Nimble SwiftyMocky Embassy EnvoyAmbassador RxBlocking 🏛️ Architecture: Multi-modular, MV MVC MVP MVVM VIPER 📋 Methodologies: Agile Scrum Kanban 🚀 CI: Bitrise Jenkins